Here is one source of green energy that I didn't include in my book, The Green Light on Green Stocks: A Quick Guide to Green Investing and Making Money in Alternative Energy Stocks. I covered everything from wind to solar to cogeneration to flywheels to cloud computing, but I didn't include body heat.
A real estate company in Stockholm, Sweden called Jernhusen, has put the heat from human bodies to good use, using it to heat a building. All the hundreds of thousands of daily passengers that go through Stockholm Central Station generate a huge amount of body heat. That heat is captured, used to heat water which is transported to another building in order to warm the secondary building. An energy savings of about 25% is claimed.
Although there is no way to invest in body heat energy yet, there are still plenty of other environmentally conscious energy producing companies. You can find free lists of green energy companies, such as ethanol stocks, cloud computing stocks, and water purification stocks, at WallStreetNewsNetwork.com. The lists can be downloaded, sorted, and updated.